Selectable band suppression for a distributed antenna system

ABSTRACT

In one embodiment, a distributed antenna system comprises at least one master unit; at least one remote antenna unit coupled to the master unit and comprising a power amplifier to radiate a remote downlink radio frequency signal, the remote antenna unit further configured to receive a remote uplink radio frequency signal from at least one antenna, the remote downlink radio frequency signal comprises first and second downlink frequency bands and wherein the remote uplink radio frequency signal comprises first and second uplink frequency bands; a band suppression module comprising: a controller; an uplink band suppression element configured to apply an attenuation to suppress the first uplink frequency band in response to a signal from the controller; and a downlink band suppression element configured to apply an attenuation to suppress the first downlink frequency band in response to the signal from the band suppression controller.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. patent application claiming priority to, andthe benefit of, U.S. Provisional Patent Application No. 62/512,541titled “SELECTABLE BAND SUPPRESSION FOR A DISTRIBUTED ANTENNA SYSTEM”filed on May 30, 2017, which is incorporated herein by reference in itsentirety.

BACKGROUND

A Distributed Antenna System (DAS) typically includes one or more masterunits that are communicatively coupled with a plurality of remoteantenna units, where each remote antenna unit can be coupled directly toone or more of the master units or indirectly via one or more otherremote antenna units and/or via one or more intermediary or expansionunits. A DAS is typically used to improve the coverage provided by oneor more base stations that are coupled to the master units. These basestations can be coupled to the master units via one or more cables orvia a wireless connection, for example, using one or more donorantennas. The wireless service provided by the base stations canincluded commercial cellular service and/or private or public safetywireless communications.

In such a safety application, the safety wireless capacity provided bythe DAS and the associated base-station-related equipment during normaloperations may not be sufficient in emergency situations (such as a fireor security event) due to the presence of many additional users of thesafety wireless service. As a result, it is common to provision a DASused for such safety applications with additional base-station-relatedand DAS equipment (base stations, repeaters, etc.) that operate in astandby mode during normal operations but can be activated in emergencysituations in order to provide increased safety wireless servicecapacity when necessary.

When planning for coverage within public safety relevant facilities byemergency services providers, the signal distributing infrastructure ofthe DAS may be shared between private and public safety services, eachoperating on their own frequency bands. For example the assignedlicensed bands for the German Public Safety Digital Radio (BDBOS) TETRAnetwork in Germany are 380-385 MHz for uplink communications and 390-395MHz in downlink communications. For private safety services, differentbands are used. For example, 415-420 MHz may be used for uplinkcommunications and 425-430 MHz may be used for downlink communicationsfor private safety services. Public safety signals are usually used bygovernment agencies, such as police or fire, and public safety coverageis available from base stations provided across large geographic regions(for example, nationwide coverage). Private safety signal coverage, incontrast, is usually found within specific facilities or other areas ofprivate service responsibility, for example, for the use of facilityoperator.

Subways, and specifically subway tubes, are one example of a facilitywhere the communication infrastructure for both public and privatesafety services are extended and distributed. It is understood thatsubway trains may operate on tracks in tunnels below ground, and also ontracks above ground. However, while coverage for private safety servicesmay be desired throughout the subway facility, distributing publicsafety communications coverage to above ground segments may causeinterference with public safety communications coverage provided byother base stations operating in that area. As such, it may be requiredby regulations that public safety communications coverage by the subwayoperator's DAS should extend only to the below ground segments of thesubway system to avoid interference with the signals from local publicsafety communications base stations operating close to the above groundsegments.

It is therefore highly desirable for remote antenna units operating inabove ground segments to be able to switch “off” the public safety band.It is also desirable to be able to selectively switch “on” the publicsafety band for those same remote antenna units for some emergency caseswhere the local base station that normally provides coverage around anabove ground segment of a subway tube fails and cannot provide publicsafety coverage in that area.

One standard solution to this problem is for each remote unit to haveseparately operated communication paths in each remote antenna unit foreach band—one for public safety coverage and one for private safetycoverage. Then, the power amplifier, low noise amplifier, and/or otherelectronics for uplink and downlink transport of the public safetycommunications band may be switched off for those remote units operatingin above ground segments. This solution has a big disadvantage howeverin terms of price since two expensive power amplifier modules (inaddition to other RF components) would be needed, one for each downlinksafety band of the remote unit. For public safety operators, thisredundant and expensive equipment remains dormant most of the time,except for when emergency situations require its operation.

SUMMARY

In one embodiment, a distributed antenna system comprises: at least onemaster unit configured to receive a base station downlink radiofrequency signal and to transmit a base station uplink radio frequencysignal; at least one remote antenna unit that is communicatively coupledto the at least one master unit, the remote antenna unit comprising apower amplifier and configured to radiate a remote downlink radiofrequency signal from at least one antenna associated with the remoteantenna unit, the remote antenna unit further configured to receive aremote uplink radio frequency signal from at least one antennaassociated with the remote antenna unit, wherein the remote downlinkradio frequency signal comprises a first downlink frequency band and asecond downlink frequency band and wherein the remote uplink radiofrequency signal comprises a first uplink frequency band and a seconduplink frequency band; a band suppression module comprising: a bandsuppression controller; an uplink band suppression element controlled bythe band suppression controller, wherein the uplink band suppressionelement is configured to apply an attenuation to suppress the firstuplink frequency band in response to a signal from the band suppressioncontroller; and a downlink band suppression element controlled by theband suppression controller, wherein the downlink band suppressionelement is configured to apply an attenuation to suppress the firstdownlink frequency band in response to the signal from the bandsuppression controller.

DRAWINGS

FIGS. 1, 1A, 1B and 1C are block diagrams illustrating a distributedantenna system of one embodiment of the present disclosure.

FIGS. 2, 2A, 2B and 2C are block diagrams illustrating example remoteantenna units of alternate embodiments of the present disclosure.

In accordance with common practice, the various described features arenot drawn to scale but are drawn to emphasize. Reference charactersdenote like elements throughout figures and text.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings that form a part hereof, and in which is shown byway of specific illustrative embodiments. These embodiments aredescribed in sufficient detail to enable those skilled in the art topractice the embodiments, and it is to be understood that otherembodiments may be utilized and that logical, mechanical and electricalchanges may be made without departing from the scope of the presentdisclosure. The following detailed description is, therefore, not to betaken in a limiting sense.

Embodiments of the present disclosure provide solutions for DASoperators to selectively disable public safety bands at select remoteunits without the need to for remote antenna units to be equipped withexpensive multiple independent signal paths. The embodiments illustratedherein present solutions that adopt a novel perspective as to what itmeans for an operating band of a DAS to be “switched off”. Morespecifically, when it is desired to disable a specific operating band,as opposed to disconnecting a signal path or de-powering downelectronics associated with that operating band, the embodimentspresented herein selectively reconfigure a signal path to suppresssignals in that operating band. For example, if the signals for a publicsafety operating band are sufficiently suppressed to a level at or belowsignal levels that would be considered a permitted spurious RF emissions(while the private safety operating band remains operable) then thepublic safety operating band has effectively been turned off withoutleaving expensive electronics components sitting idle and unutilizedwithin the remote antenna unit.

For example, in the field of commercial cellular communications, asignal emission having a power level of −36 dBm or less from a basestation or remote antenna unit would be considered an acceptablespurious emission at the antenna. Other examples of acceptable maximumpermitted levels of spurious emissions for different applications andradio frequency equipment may be found in InternationalTelecommunications Union recommendation ITU-R SM.329-7 which is hereinincorporated by reference in its entirety.

Assuming a remote antenna unit is designed to transmit from its antennaa downlink signal (DL1) at the output power level of +30 dBm per carrierin a first band, DL1, and that signal values below −36 dBm at theantenna port are considered an acceptable spurious emission, then tosuppress the DL1 frequencies, the DL1 band could attenuated by 66 dB ormore (+30 dBm−(−36 dBm)=66 dB) to reach values below −36 dBm at theantenna port. Thus, if this example remote antenna unit includes a bandsuppression module that selectively applies an attenuation of 66 dB tothe DL1 band, it can effectively suppressed and turn off the DL1 band.

FIG. 1 is block diagram of one exemplary embodiment of a distributedantenna system (DAS) 100 where the remote antenna units utilize bandsuppression modules as described herein. As shown in FIG. 1, the DAS 100comprises one or more master units 110 that are communicatively coupledto one or more remote antenna units 112 via one or more cables 114. Insome embodiments, the cables 114 discussed herein may each operatebidirectionally with downlink and uplink communications carried over thecable. It should also be understood, however, that in other embodiments,a cable 114 may itself further comprise a pair of cables including anuplink cable for uplink communication, and a downlink cable for downlinkcommunication. Each remote antenna unit 112 can be communicativelycoupled directly to one or more of the master units 110 or indirectlyvia one or more other remote antenna units 112 and/or via one or moreintermediary or expansion units 113.

Each master unit 110 is communicatively coupled to one or more basestations 140. One or more of the base stations 140 can be co-locatedwith the respective master units 110 to which it is coupled (forexample, where the base station 140 is dedicated to providing basestation capacity to the DAS 100 and is coupled to the respective masterunits 110). Also, one or more of the base stations 140 can be locatedremotely from the respective master units 110 to which it is coupled(for example, where the base station 140 provides base station capacityto an area beyond the coverage area of the DAS 100). In this lattercase, the master unit 110 can be coupled to a donor antenna and repeateror bi-directional amplifier in order to wirelessly communicate with theremotely located base station 140.

In this exemplary embodiment, the base stations 140 include one or morebase stations that are used to provide public and/or private safetywireless services (for example, wireless communications used byemergency services organizations (such as police, fire and emergencymedical services) to prevent or respond to incidents that harm orendanger persons or property). Such base stations are also referred tohere as “safety wireless service base stations” or “safety basestations.” The base stations 140 also can include, in addition to safetybase stations, one or more base stations that are used to providecommercial cellular wireless service. Such base stations are alsoreferred to here as “commercial wireless service base stations” or“commercial base stations.”

The base stations 140 can be coupled to the master units 110 using anetwork of attenuators, combiners, splitters, amplifiers, filters,cross-connects, etc., (sometimes referred to collectively as a“point-of-interface” or “POI”). This network can be included in themaster units 110 and/or can be separate from the master units 110. Thisis done so that, in the downlink, the desired set of RF channels outputby the base stations 140 can be extracted, combined, and routed to theappropriate master units 110, and so that, in the upstream, the desiredset of carriers output by the master units 110 can be extracted,combined, and routed to the appropriate interface of each base station140. It is to be understood, however, that this is one example and thatother embodiments can be implemented in other ways.

As shown in FIG. 1A, in general, each master unit 110 comprises downlinkDAS circuitry 111 that is configured to receive one or more downlinksignals from one or more base stations 140. These signals are alsoreferred to here as “base station downlink signals.” Each base stationdownlink signal includes one or more radio frequency channels used forcommunicating in the downlink direction with user equipment 116 (such astablets or cellular telephone, for example) over the relevant wirelessair interface. Typically, each base station downlink signal is receivedas an analog radio frequency signal, though in some embodiments one ormore of the base station signals are received in a digital form (forexample, in a digital baseband form complying with the Common PublicRadio Interface (“CPRI”) protocol, Open Radio Equipment Interface(“ORP”) protocol, the Open Base Station Standard Initiative (“OBSAI”)protocol, or other protocol). The downlink DAS circuitry 111 in eachmaster unit 110 is also configured to generate one or more downlinktransport signals derived from one or more base station downlink signalsand to transmit one or more downlink transport signals to one or more ofthe remote antenna units 112.

As shown in FIG. 1B, each remote antenna unit 112 comprises downlink DAScircuitry 118 that is configured to receive the downlink transportsignals transmitted to it from one or more master units 110 and to usethe received downlink transport signals to generate one or more downlinkradio frequency signals that are radiated from one or more antennas 119associated with that remote antenna unit 112 for reception by userequipment 116. These downlink radio frequency signals are analog radiofrequency signals and are also referred to here as “remote downlinkradio frequency signals.” Each remote downlink radio frequency signalincludes one or more of the downlink radio frequency channels used forcommunicating with user equipment 116 over the wireless air interface.In this way, the DAS 100 increases the coverage area for the downlinkcapacity provided by the base stations 140.

Also, each remote antenna unit 112 comprises uplink DAS circuitry 121that is configured to receive via antenna 119 one or more uplink radiofrequency signals transmitted from the user equipment 116. These signalsare analog radio frequency signals and are also referred to here as“remote uplink radio frequency signals.” Each uplink radio frequencysignal includes one or more radio frequency channels used forcommunicating in the uplink direction with user equipment 116 over therelevant wireless air interface. The uplink DAS circuitry 121 in eachremote antenna unit 112 is also configured to generate one or moreuplink transport signals derived from the one or more remote uplinkradio frequency signals and to transmit one or more uplink transportsignals to one or more of the master units 110.

Each master unit 110 comprises uplink DAS circuitry 124 that isconfigured to receive the respective uplink transport signalstransmitted to it from one or more remote antenna units 112 and to usethe received uplink transport signals to generate one or more basestation uplink radio frequency signals that are provided to the one ormore base stations 140 associated with that master unit 110. Typically,this involves, among other things, combining or summing uplink signalsreceived from multiple remote antenna units 112 in order to produce thebase station signal provided to each base station 140. Each base stationuplink signal includes one or more of the uplink radio frequencychannels used for communicating with user equipment 116 over thewireless air interface. In this way, the DAS 100 increases the coveragearea for the uplink capacity provided by the base stations 140.

As shown in FIG. 1C, each expansion unit 113 comprises downlink DAScircuitry 126 that is configured to receive the downlink transportsignals transmitted to it from the master unit 110 (or other expansionunit 113) and transmits the downlink transport signals to one or moreremote antenna units 112 or other downstream intermediary units 113.Each expansion unit 113 comprises uplink DAS circuitry 128 that isconfigured to receive the respective uplink transport signalstransmitted to it from one or more remote antenna units 112 or otherdownstream intermediary units 113, combine or sum the received uplinktransport signals, and transmit the combined uplink transport signalsupstream to the master unit 110 or other expansion unit 113. In someembodiments, one or more remote antenna units 112 may be coupled to theone or more master units 110 via one or more other remote antenna units112 (for examples, where the remote antenna units 112 are coupledtogether in a daisy chain or ring topology). In such an embodiments, anexpansion unit 113 may be implemented using a remote antenna units 112.

The downlink DAS circuitry 111, 118, and 126 and uplink DAS circuitry124, 121, and 128 in each master unit 110, remote antenna unit 112, andexpansion unit 113, respectively, can comprise one or more appropriateconnectors, attenuators, combiners, splitters, amplifiers, filters,duplexers, analog-to-digital converters, digital-to-analog converters,mixers, field-programmable gate arrays (FPGAs), microprocessors,transceivers, framers, etc., to implement the features described above.Also, the downlink DAS circuitry 111, 118, and 126 and uplink DAScircuitry 124, 121, and 128 may share common circuitry and/orcomponents. For example, some components (such as duplexers) by theirnature are shared among the downlink DAS circuitry 111, 118, and 126 anduplink DAS circuitry 124, 121, and 128.

The DAS 100 can use either digital transport, analog transport, orcombinations of digital and analog transport for generating andcommunicating the transport signals between the master units 110, theremote antenna units 112, and any intermediary units 113. For thepurposes of illustration, some of the embodiments described here areimplemented using analog transport over optical cables. However, it isto be understood that other embodiments can be implemented in otherways, for example, in DASs that use other types of analog transport (forexample, using other types of cable and/or using analog transport thatmakes use of frequency shifting), digital transport (for example, wheredigital samples indicative of the analog base station radio frequencysignals and analog remote radio frequency signals are generated andcommunicated between the master units 110 and the remote antenna units112), or combinations of analog and digital transport.

Each unit 110, 112, 113 in the DAS 100 can also comprises a respectivecontroller 130. The controller 130 is implemented using one or moreprogrammable processors that execute software that is configured toimplement the various features described here as being implemented bythe controller 130. The controller 130, the various features describedhere as being implemented by the controller 130, or portions thereof,can be implemented in other ways (for example, in a field programmablegate array (FPGA), application specific integrated circuit (ASIC),etc.).

Each controller 130 is configured to monitor and control the operationof the associated unit. Each controller 130 is also configured to sendand receive management data over the DAS 100. In one embodiment, eachunit 110, 112, 113 in the DAS 100 also comprises a modem 135 that isconfigured to send and receive management data over the DAS 100 bymodulating and demodulating one or more carrier frequencies that areused for the purpose of communicating management data. In someembodiments (for example, where digital transport is used in the DAS), aseparate modem 135 for modulating and demodulating management data isnot used and, instead, the management data is combined with the digitalDAS transport data before being supplied to the transport transceiver orother physical layer device.

One or more of the units 110, 112, 113 in the DAS 100 also comprise aninterface 150 to couple the controller 130 in that unit 110, 112, 113 toan operator control panel 131 that is deployed near that unit 110, 112,113. The interface 150 is therefore also referred to here as an “OCPinterface 150.” Each such unit 110, 112, 113 can include an appropriateconnector to attach a cable 152 (also referred to here as an “OCP cable152”) that is used to couple the unit 110, 112, 113 to the OCP 131. Ingeneral, each OCP 131 can be connected to the nearest unit 110, 112, 113of the DAS 110.

As mentioned above, in addition to potentially providing commercialconnectivity to users via consumer bands, DAS 110 also distributespublic safety connectivity coverage and private safety communicationcoverage. In the exemplary embodiment shown in FIG. 1, each remote unit112 includes a band suppression module (BSM) 120 that selectivelyapplies an attenuation to specific uplink and/or downlink bands toeffectively turn off those bands.

FIG. 2 is a simplified diagram illustrating remote antenna unit 200 ofone embodiment of the present disclosure that may be used to implementany one of the remote units 112 of the DAS 100 described above inconnection with FIG. 1 and operate in conjunction with the master unit110 shown in FIG. 1. In the particular embodiment shown in FIG. 2,remote antenna unit 200 comprises least one optical transceiverinterface (OTRX) 210 for communicating via optical fiber with the masterunit 110. It should be appreciated that in other embodiments, the masterunit 110 and remote unit 200 may communicate over other types of wiringor cables. Remote antenna unit 200 further comprises an RF poweramplifier 211, a downlink signal diplexer 212, an antenna port 215 thatis configured to couple to remote unit 200 to an antenna 119, an uplinksignal diplexer 217, a low noise amplifier (LNA) 122, and a bandsuppression module 120. Power amplifier 211 power amplifies downlinksignals to a desired power level and feeds it to antenna 119 to radiateto user equipment 116 (not shown in FIG. 2) via diplexer 212. Uplinkradio frequency signals transmitted from user equipment 116 in thecoverage area of the remote antenna unit 200 are received via theassociated antenna 119 and provided to LNA 122, which amplifies thereceived uplink signals. The downlink signal diplexer 212 comprises afirst band filter 213 that filters out signals having a frequencyoutside of the first DL band (DL1) and a second band pass filter 214that filters out signals having a frequency outside of the second DLband (DL2). For example, in one embodiment, the DL1 band may passthrough only public safety coverage signals (e.g. in the 390-395 MHzband) while the DL2 band may pass through only private safety coveragesignals (e.g. in the 425-430 MHz band). As such, though the poweramplifier 211 may output a broad range of amplified signals, only thosesignals in frequency bands for which DAS 100 is authorized to transmitwill pass to the antenna port 215 and radiate from antenna 119.Similarly, the uplink signal diplexer 217 comprises a first band passfilter 218 and a second band pass filter 219. In one embodiment, the UL1band may pass through only public safety coverage signals (e.g. in the380-385 MHz band) while the UL2 band may pass through only privatesafety coverage signals (e.g. in the 415-420 MHz band). As such, the UL1and UL2 signals received by antenna 119 may pass to the low noiseamplifier without high power downlink signals saturating the uplink pathelectronics of the remote antenna unit 200.

Band suppression module 120 switches between two or more modes. Forexample, in a first mode, band suppression module 120 may be switched toselectively apply an attenuation to suppress the DL1 and UL1 bands(which may be associated with public safety coverage signals, forexample) while allowing the DL2 and UL2 bands (which may be associatedwith the private safety coverage signals, for example) to pass. In asecond mode, band suppression module 120 may be switched to allow DL1and UL1 bands and the DL2 and UL2 bands to pass. In some embodiments, athird mode may optionally be provided to selectively apply anattenuation to suppress the DL2 and UL2 bands while allowing the DL1 andUL1 bands to pass.

Band suppression module 120, the various features described here asbeing implemented by the band suppression module 120, or portionsthereof, can be implemented by RF electronics in combination with forexample, control circuitry and/or code executed in a processor, in afield programmable gate array (FPGA), application specific integratedcircuit (ASIC), etc. In the embodiment shown in FIG. 2, the bandsuppression module 120 includes at least one switchable RF downlink bandsuppression element 222, at least one switchable RF uplink bandsuppression element 223, and a band suppression controller 230. In someembodiments, the band suppression controller 230 may be implemented withelectronics responsive to signals from the remote unit controller 130.In some embodiments, the band suppression controller 230 may beimplemented at least in part as a software application executed by thecontroller 130. The downlink and uplink band suppression elements 222and 223 may be implemented in varies ways, for example by switchablenotch filters or band pass filters, or using hybrid couplers orcirculators with switchable loads.

For example, FIG. 2A illustrates an example embodiment of the remoteantenna unit 200 where the band suppression elements 222 and 223 of theband suppression module 120 are implemented using an RF network element234 (such as a circulator or hybrid coupler, for example) with at leastone switchable load 232 that may be selected or deselect by bandsuppression controller 230. For example, in one embodiment, a downlinksignal having DL1 and DL2 band components is received at bandsuppression element 222. When suppression of public safety coveragesignals is needed, band suppression controller 230 switches in theswitchable load 232 so that the band suppression element 222 transmitsthe downlink signal having DL1 and DL2 into the switchable load 232.Switchable load 232 is tuned to absorb RF signals in the DL1 band sothat any component of DL1 exiting out from switchable load 232 isattenuated below a threshold power level (for example, a level at whichthe signal would be considered a spurious emission). For the Examplediscussed above where the power amplifier 211 nominally delivers a +30dBm signal per carrier to the antenna 119, the switchable load 232attenuates the DL1 signal it receives by 66 dB so that the whenattenuated DL1 signal is provided to the power amplifier 211 and thenradiated by antenna 119, the transmitted power of the DL1 signal is ator below −36 dBm at the antenna port 215. These attenuation values areprovided as illustrative examples only. One of ordinary skill in the artwould be able to determine the threshold power level for the signal tobe considered negligible (e.g. at or below a level of a spuriousemission). It also should be appreciated that switchable load 232 maycomprise multiple load elements coupled together in order to achieve theattenuation desired. In one embodiment, when suppression of publicsafety coverage signals is not desired, band suppression controller 230can switch out the switchable load 232 so that the band suppressionelement 222 bypasses switchable load 232 and thus transmits the downlinksignal having both DL1 and DL2 to power amplifier 211 so that DL1 andDL2 signals are provided to the power amplifier 211 and then radiated byantenna 119 at full nominal power (e.g. +30 dBm signal per carrier).

Similarly, in one embodiment, an uplink signal having UL1 and UL2 bandcomponents is received at band suppression element 223. When suppressionof public safety coverage signals is needed, band suppression controller230 switches in the switchable load 233 so that the band suppressionelement 223 transmits the uplink signal having UL1 and UL2 into theswitchable load 233. Switchable load 233 is tuned to absorb RF signalsin the UL1 band so that any component of UL1 exiting out from switchableload 233 is attenuated below a threshold power level (for example, alevel at which the signal would be considered a spurious emission). Oneof ordinary skill in the art would be able to determine the thresholdpower level for the signal to be considered negligible (e.g. at or belowa level of a spurious emission). It also should be appreciated thatswitchable load 233 may comprise multiple load elements coupled togetherin order to achieve the attenuation desired. When suppression of publicsafety coverage signals is not desired, band suppression controller 230switches out the switchable load 233 so that the band suppressionelement 223 bypasses switchable load 233 and thus transmits the uplinksignal having both UL1 and UL2 to the master unit 110, which thenproceeds up to base station 140.

FIG. 2B illustrates another example embodiment of the remote antennaunit 200 where the band suppression elements 222 and 223 of the bandsuppression module 120 are implemented using RF band pass filters. Inthis example embodiment, band suppression module 120 comprises adownlink signal path that includes a downlink band pass filter element242, a first matching attenuator 243 having an insertion loss equivalentto the insertion loss of the downlink band pass filter element 242, andone or more downlink suppression selection switches 244 coupled to andoperated by the band suppression controller 230. Band suppression module120 further comprises an uplink signal path that includes an uplink bandpass filter element 245, a second matching attenuator 246 having aninsertion loss equivalent to the insertion loss of the uplink band passfilter element 245, and one or more uplink suppression selectionswitches 247 coupled to an operated by the band suppression controller230.

In one embodiment, a downlink signal having DL1 and DL2 band componentsis received at band suppression element 222. When suppression of publicsafety coverage signals is needed, band suppression controller 230switches the one or more downlink suppression selection switches 244 sothat the downlink signal having DL1 and DL2 band components istransmitted into the downlink band pass filter element 242.

Downlink band pass filter 242 is tuned to pass the DL2 band but filterout RF signals in the DL1 band so that any component of DL1 exiting outfrom downlink band pass filter 242 is attenuated below a threshold powerlevel (for example, a level at which the signal would be considered aspurious emission). One of ordinary skill in the art would be able todetermine the threshold power level for the signal to be considerednegligible (e.g. at the level of a spurious emission). When suppressionof public safety coverage signals is not desired, band suppressioncontroller 230 switches the one or more downlink suppression selectionswitches 244 so that the downlink signal having DL1 and DL2 bandcomponents is instead transmitted through the first matching attenuator243 to the power amplifier 211 so that DL1 and DL2 signals are providedto the power amplifier 211 and then radiated by antenna 119 at fullnominal power (e.g. +30 dBm signal per carrier). Because the firstmatching attenuator 243 comprises an insertion loss equivalent to theinsertion loss of the downlink band pass filter 242, there is no changein the power level of the DL2 (private safety cover signal) transmittedby remote antenna unit 200 due to the switching the DL1 band between theon (i.e. full nominal power) or off (i.e. suppressed) states.

In one embodiment, an uplink signal having UL1 and UL2 band componentsis received at band suppression element 223. When suppression of publicsafety coverage signals is needed, band suppression controller 230switches the one or more uplink suppression selection switches 247 sothat the uplink signal having UL1 and UL2 band components is transmittedinto the uplink band pass filter 245.

Uplink band pass filter 245 is tuned to pass the UL2 band but filter outRF signals in the UL1 band so that any component of UL1 exiting out fromuplink band pass filter 245 is attenuated below a threshold power level(for example, a level at which the signal would be considered a spuriousemission). One of ordinary skill in the art would be able to determinethe threshold power level for the signal to be considered negligible(e.g. at the level of a spurious emission). When suppression of publicsafety coverage signals is not desired, band suppression controller 230switches the one or more uplink suppression selection switches 247 sothat the uplink signal having UL1 and UL2 band components is insteadtransmitted through the second matching attenuator 246 so that UL1 andUL2 signals are provided from the LNA 122 to the OTRX 210 and thentransmitted to the master unit 110. Because the second matchingattenuator 246 comprises an insertion loss equivalent to the insertionloss of the uplink band pass filter 245, there is no change in the powerlevel of the UL2 (private safety cover signal) received by the masterunit 110 due to the switching the UL1 band between on (i.e. nominalpower) or off (i.e. suppressed) states.

In one embodiment, band suppression controller 230 responds tomanagement data which may be received by DAS 100 is multiple differentways. For example, in one embodiment, DAS 100 receives management datafor activating or deactivating the UL1 and DL1 bands for select RAUs 112through input entered by an operator into one of the OCP 131 coupled tothe master unit 110 via OCP interface 150, an RAU 112, or an expansionunit 113. Alternatively, management data for activating or deactivatingthe UL1 and DL1 bands may be communicated via one of the modems 135 usedfor the purpose of communicating management data. As anotheralternative, management data for activating or deactivating the UL1 andDL1 bands may be received by the master unit 110 from one of the basestations 140. Management data comprising instruction toactivate/deactivate the UL1 and DL1 bands may then be transmitted to theaffected RAU 112 where the controller 230 responds by suppressing theUL1 and DL1 bands (for example, in any manner discussed above).

In some embodiments, instruction to activate/deactivate the UL1 and DL1bands are addressed to specific RAU 112 of the DAS 100 so that onlythose RAU 112 respond to the instructions. In other embodiments, theband suppression module 120 in one or more of the RAU 112 may beprogrammed with a default and one or more emergency event configurationsthat depend on their physical location. For example, a first RAU 112 ofDAS 100 may be physically located inside a facility, but at a locationwhere one or more of its operating bands can potentially interfere withthose of local base stations outside of the facility (for example, thefirst RAU 112 is located in an above ground segment of a subway system).The band suppression controller 230 may have stored in a memory 231 adefault first configuration with settings that configure BSM 120 tosuppress UL1 and DL1 under nominal default conditions, and a secondconfiguration with settings that configured BSM 120 to pass UL1 and DL1without suppression under a specified event condition. At the same time,a second RAU 112 of DAS 100 may be physically located inside a facilityat a position where it cannot interfere with those of local basestations outside of the facility (for example, the second RAU 112 islocated in an underground segment of a subway system). The bandsuppression controller 230 for this second RAU 112 may have stored inmemory 231 a default first configuration with setting that configure itsBSM 120 to pass UL1 and DL1 without suppression under nominal defaultconditions, and a second configuration with setting that also configureBSM 120 to pass UL1 and DL1 without suppression under the specifiedevent condition. In this way, the DAS 100 may simply communicate blanketmessage to all RAU 112 to either enter an event configuration state, orreturn to their default configuration state, and each RAU 112 willrespond accordingly and consistent with how the default configurationand event configuration are particularly defined within their specificBSM 120. It should also be understood that more than one eventconfiguration may be defined within each RAU 112 and the RAU 112 couldtherefor configure itself based on which event is identified in theactivate/deactivate instruction it receives.

FIG. 2C illustrates another example embodiment of the remote antennaunit 200 where the band suppression module 120 can be switched intomultiple alternate modes where either the UL1 & DL1 bands aresuppressed, the UL2 & DL2 bands are suppressed, or neither set of bandsare suppressed.

In this example embodiment, band suppression module 120 comprises adownlink signal path that includes a first downlink band pass filterelement 242-1, a second downlink band pass filter element 242-2, a firstmatching attenuator 243 having an insertion loss equivalent to theinsertion loss of the downlink band pass filter elements 242-1 and242-2, and one or more downlink suppression selection switches 264coupled to and operated by the band suppression controller 230. Bandsuppression module 120 further comprises an uplink signal path thatincludes a first uplink band pass filter element 245-1, a second uplinkband pass filter element 245-2, a second matching attenuator 246 havingan insertion loss equivalent to the insertion loss of the uplink bandpass filter elements 245-1 and 245-2, and one or more uplink suppressionselection switches 267 coupled to an operated by the band suppressioncontroller 230.

In one embodiment, a downlink signal having DL1 and DL2 band componentsis received at band suppression element 222. When suppression of the DL1band is needed, band suppression controller 230 switches the one or moredownlink suppression selection switches 264 so that the downlink signalhaving DL1 and DL2 band components is transmitted into the downlink bandpass filter element 242-1. Downlink band pass filter 242-1 is tuned topass the DL2 band but filter out RF signals in the DL1 band so that anycomponent of DL1 exiting out from downlink band pass filter 242 isattenuated below a threshold power level (for example, a level at whichthe signal would be considered a spurious emission). When suppression ofthe DL2 band is needed, band suppression controller 230 switches the oneor more downlink suppression selection switches 264 so that the downlinksignal having DL1 and DL2 band components is transmitted into thedownlink band pass filter element 242-2. Downlink band pass filter 242-2is tuned to pass the DL1 band but filter out RF signals in the DL2 bandso that any component of DL2 exiting out from downlink band pass filter242 is attenuated below a threshold power level (for example, a level atwhich the signal would be considered a spurious emission). One ofordinary skill in the art would be able to determine the threshold powerlevel for the signal to be considered negligible (e.g. at the level of aspurious emission).

When suppression of neither DL1 nor DL2 is desired, band suppressioncontroller 230 switches the one or more downlink suppression selectionswitches 264 so that the downlink signal having DL1 and DL2 bandcomponents is instead transmitted through the first matching attenuator243 to the power amplifier 211 so that DL1 and DL2 signals are providedto the power amplifier 211 and then radiated by antenna 119 at fullnominal power (e.g. +30 dBm signal per carrier). Because the firstmatching attenuator 243 comprises an insertion loss equivalent to theinsertion loss of the downlink band pass filter 242-1 and/or downlinkband pass filter 242-2, there is no change in the power level of the DL1or DL2 signals transmitted by remote antenna unit 200 due to theswitching.

In one embodiment, an uplink signal having UL1 and UL2 band componentsis received at band suppression element 223. When suppression of the UL1band is needed, band suppression controller 230 switches the one or moreuplink suppression selection switches 267 so that the uplink signalhaving UL1 and UL2 band components is transmitted into the uplink bandpass filter 245-1. Uplink band pass filter 245-1 is tuned to pass theUL2 band but filter out RF signals in the UL1 band so that any componentof UL1 exiting out from uplink band pass filter 245-1 is attenuatedbelow a threshold power level (for example, a level at which the signalwould be considered a spurious emission). When suppression of the UL2band is needed, band suppression controller 230 switches the one or moreuplink suppression selection switches 267 so that the uplink signalhaving UL1 and UL2 band components is transmitted into the uplink bandpass filter 245-2. Uplink band pass filter 245-2 is tuned to pass theUL1 band but filter out RF signals in the UL2 band so that any componentof UL2 exiting out from uplink band pass filter 245-2 is attenuatedbelow a threshold power level. One of ordinary skill in the art would beable to determine the threshold power level for the signal to beconsidered negligible (e.g. at the level of a spurious emission).

When suppression of neither UL1 or UL2 is desired, band suppressioncontroller 230 switches the one or more uplink suppression selectionswitches 267 so that the uplink signal having UL1 and UL2 bandcomponents is instead transmitted through the second matching attenuator246 so that UL1 and UL2 signals are provided from the LNA 122 to theOTRX 210 and then transmitted to the master unit 110. Because the secondmatching attenuator 246 comprises an insertion loss equivalent to theinsertion loss of the uplink band pass filter 245-1 and/or uplink bandpass filter 245-2, there is no change in the power level of the UL1 orUL2 signals transmitted by remote antenna unit 200 due to the switching.

It should also be appreciated that other network architectures may beimplemented that still functionally operate in the same manner asdescribed in any of the embodiments described herein. It should also beunderstood that for any of the embodiments described herein, while thecommunication links connecting master units and remote antenna units maycomprise optical fiber, in other embodiments other wired or wirelesscommunication links, or combinations thereof, may be utilized insteadof, or in combination with, optical fiber communication links.

As used herein, DAS related terms such as “master unit”, “remote unit”,“remote antenna unit” and “control unit” and “controller” refer tohardware elements that would be immediately recognized and understood bythose of skill in the art of wireless communications and are not usedherein as nonce words or nonce terms for the purpose of invoking 35 USC112(f).

Example Embodiments

Example 1 includes a distributed antenna system, the system comprising:at least one master unit configured to receive a base station downlinkradio frequency signal and to transmit a base station uplink radiofrequency signal; at least one remote antenna unit that iscommunicatively coupled to the at least one master unit, the remoteantenna unit comprising a power amplifier and configured to radiate aremote downlink radio frequency signal from at least one antennaassociated with the remote antenna unit, the remote antenna unit furtherconfigured to receive a remote uplink radio frequency signal from atleast one antenna associated with the remote antenna unit, wherein theremote downlink radio frequency signal comprises a first downlinkfrequency band and a second downlink frequency band and wherein theremote uplink radio frequency signal comprises a first uplink frequencyband and a second uplink frequency band; a band suppression modulecomprising: a band suppression controller; an uplink band suppressionelement controlled by the band suppression controller, wherein theuplink band suppression element is configured to apply an attenuation tosuppress the first uplink frequency band in response to a signal fromthe band suppression controller; and a downlink band suppression elementcontrolled by the band suppression controller, wherein the downlink bandsuppression element is configured to apply an attenuation to suppressthe first downlink frequency band in response to the signal from theband suppression controller.

Example 2 includes the system of example 1, wherein the first downlinkfrequency band and the first uplink frequency band define a publicsafety communications band, and where the second downlink frequency bandand the second uplink frequency band define a private safetycommunications band.

Example 3 includes the system of any of examples 1-2, wherein the bandsuppression controller comprises electronics responsive to a managementsignal received by the distributed antenna system, wherein the bandsuppression controller controls one or both of the uplink bandsuppression element and the downlink band suppression element inresponse to the management signal.

Example 4 includes the system of any of examples 1-3, wherein the bandsuppression module further comprises a memory coupled to the bandsuppression controller, the memory storing a plurality of configurationsetting; wherein the band suppression controller selectively reads aconfiguration setting from the memory to control the uplink bandsuppression element and the downlink band suppression element.

Example 5 includes the system of any of examples 1-4, wherein the uplinkband suppression element and the downlink band suppression element eachfurther comprise: an RF network element; and at least one switchableload coupled to the RF network element; wherein the band suppressioncontroller is configured to control application of the at least oneswitchable load to suppress one of the first uplink signal or the firstdownlink signal.

Example 6 includes the system of example 5, wherein the RF networkelement comprises either a circulator or a hybrid coupler.

Example 7 includes the system of any of examples 1-6, wherein the uplinkband suppression element and the downlink band suppression element eachfurther comprise: a band pass filter; a matching attenuator having aninsertion loss equivalent to an insertion loss of the band pass filter;and one or more suppression selection switches coupled to the band passfilter and the matching attenuator, wherein the band suppressioncontroller is configured to control the one or more suppressionselection switches to toggle between the band pass filter and thematching attenuator.

Example 8 includes the system of any of examples 1-7, wherein the uplinkband suppression element is further configured to pass the second uplinkfrequency band and the downlink band suppression element is furtherconfigured to pass the second downlink frequency band.

Example 9 includes the system of any of examples 1-8, wherein the uplinkband suppression element and the downlink band suppression element eachfurther comprise: a first band pass filter; a second band pass filter; amatching attenuator having an insertion loss equivalent to an insertionloss of either the first band pass filter or the second band passfilter; and one or more suppression selection switches coupled to theband pass filter and the matching attenuator, wherein the bandsuppression controller is configured to control the one or moresuppression selection switches to switch between selection of the firstband pass filter, the second band pass filter, of the matchingattenuator, in response to the signal from the band suppressioncontroller.

Example 10 includes a method for selectable band suppression for adistributed antenna system comprising at least one master unit and atleast one remote antenna unit that is communicatively coupled to the atleast one master unit, the at least one remote antenna unit carrying aremote downlink radio frequency signal comprising a first downlinkfrequency band and a second downlink frequency band, and a remote uplinkradio frequency signal comprising a first uplink frequency band and asecond uplink frequency band, the method comprising: determining whetherthe distributed antenna system is operating under a first statuscondition or a second status condition; when the distributed antennasystem is determined to be operating under the first status condition,controlling at least one radio frequency (RF) band suppression elementto suppress the first downlink frequency band and the first uplinkfrequency band while passing the second downlink frequency band and thesecond uplink frequency band; when the distributed antenna system isdetermined to be operating under the second status condition,controlling at least one radio frequency (RF) band suppression elementto pass the first downlink frequency band, the first uplink frequencyband, the second downlink frequency band and the second uplink frequencyband.

Example 11 includes the method of example 10, wherein the first downlinkfrequency band and the first uplink frequency band define a publicsafety communications band, and where the second downlink frequency bandand the second uplink frequency band define a private safetycommunications band.

Example 12 includes the method of any of examples 10-11, wherein the atleast one remote antenna unit comprises a band suppression modulecomprising: a band suppression controller; an uplink band suppressionelement controlled by the band suppression controller, wherein theuplink band suppression element is configured to apply an attenuation tosuppress the first uplink frequency band in response to a signal fromthe band suppression controller; and a downlink band suppression elementcontrolled by the band suppression controller, wherein the downlink bandsuppression element is configured to apply an attenuation to suppressthe first downlink frequency band in response to the signal from theband suppression controller.

Example 13 includes the method of example 12, further comprising:generating the signal from the in response to a management signalreceived by the band suppression controller.

Example 14 includes the method of any of examples 12-13, furthercomprising: in response to determining whether the distributed antennasystem is operating under a first status condition or a second statuscondition, reading a configuration setting from a memory; andcontrolling the uplink band suppression element and the downlink bandsuppression element based on the configuration setting.

Example 15 includes the method of any of examples 12-14, wherein theuplink band suppression element and the downlink band suppressionelement each further comprise: an RF network element; and at least oneswitchable load coupled to the RF network element; wherein the bandsuppression controller is configured to control application of the atleast one switchable load to suppress one of the first uplink signal orthe first downlink signal.

Example 16 includes the method of example 16, wherein the RF networkelement comprises either a circulator or a hybrid coupler.

Example 17 includes the method of any of examples 12-16, wherein theuplink band suppression element and the downlink band suppressionelement each further comprise: a band pass filter; a matching attenuatorhaving an insertion loss equivalent to an insertion loss of the bandpass filter; and one or more suppression selection switches coupled tothe band pass filter and the matching attenuator, wherein the bandsuppression controller is configured to control the one or moresuppression selection switches to toggle between the band pass filterand the matching attenuator.

Example 18 includes the method of any of examples 12-17, furthercomprising determining whether the distributed antenna system isoperating under the first status condition, the second status condition,or a third condition; when the distributed antenna system is determinedto be operating under the third status condition, controlling at leastone radio frequency (RF) band suppression element to suppress the seconddownlink frequency band and the second uplink frequency band whilepassing the first downlink frequency band and the first uplink frequencyband.

Example 19 includes the method of example 18, wherein the at least oneremote antenna unit comprises a band suppression module comprising: aband suppression controller; an uplink band suppression elementcontrolled by the band suppression controller, wherein the uplink bandsuppression element is configured to apply an attenuation to selectivelysuppress either the first uplink frequency band or the second uplinkfrequency band in response to a signal from the band suppressioncontroller; and a downlink band suppression element controlled by theband suppression controller, wherein the downlink band suppressionelement is configured to apply an attenuation to selectively suppresseither the first downlink frequency band or the second downlinkfrequency band in response to the signal from the band suppressioncontroller.

Example 20 includes the method of example 19, wherein the uplink bandsuppression element and the downlink band suppression element eachfurther comprise: a first band pass filter; a second band pass filter; amatching attenuator having an insertion loss equivalent to an insertionloss of either the first band pass filter or the second band passfilter; and one or more suppression selection switches coupled to thefirst band pass filter, the second band pass filter, and the matchingattenuator, wherein the band suppression controller is configured tocontrol the one or more suppression selection switches to switch betweenselection of the first band pass filter, the second band pass filter, orthe matching attenuator, in response to the signal from the bandsuppression controller.

Example 21 includes a band suppression module for a distributed antennasystem, the module comprising: a band suppression controller; an uplinkradio frequency band suppression element controlled by the bandsuppression controller, wherein the uplink band suppression element isconfigured to apply an attenuation to suppress a first downlinkfrequency band in response to a signal from the band suppressioncontroller while passing a second downlink frequency band; and adownlink radio frequency band suppression element controlled by the bandsuppression controller, wherein the uplink band suppression element isconfigured to apply an attenuation to suppress the first downlinkfrequency band in response to the signal from the band suppressioncontroller while passing a second uplink frequency band.

Example 22 includes the module of example 21, wherein the bandsuppression controller comprises electronics responsive to a managementsignal received by the distributed antenna system, wherein the bandsuppression controller controls one or both of the uplink bandsuppression element and the downlink band suppression element inresponse to the management signal.

Example 23 includes the module of any of examples 21-22, wherein theband suppression module further comprises a memory coupled to the bandsuppression controller, the memory storing a plurality of configurationsetting; wherein the band suppression controller selectively reads aconfiguration setting from the memory to control the uplink bandsuppression element and the downlink band suppression element.

Example 24 includes the module of any of examples 21-23, wherein theuplink band suppression element and the downlink band suppressionelement each further comprise: an RF network element; and at least oneswitchable load coupled to the RF network element; wherein the bandsuppression controller is configured to control application of the atleast one switchable load to suppress one of the first uplink signal orthe first downlink signal.

Example 25 includes the module of example 24, wherein the RF networkelement comprises either a circulator or a hybrid coupler.

Example 26 includes the module of any of examples 21-25, wherein theuplink band suppression element and the downlink band suppressionelement each further comprise: a band pass filter; a matching attenuatorhaving an insertion loss equivalent to an insertion loss of the bandpass filter; and one or more suppression selection switches coupled tothe band pass filter and the matching attenuator, wherein the bandsuppression controller is configured to control the one or moresuppression selection switches to toggle between the band pass filterand the matching attenuator.

Example 27 includes the module of any of examples 21-26, wherein theuplink band suppression element and the downlink band suppressionelement each further comprise: a first band pass filter; a second bandpass filter; a matching attenuator having an insertion loss equivalentto an insertion loss of either the first band pass filter or the secondband pass filter; and one or more suppression selection switches coupledto the first band pass filter, the second band pass filter, and thematching attenuator, wherein the band suppression controller isconfigured to control the one or more suppression selection switches toswitch between selection of the first band pass filter, the second bandpass filter, or the matching attenuator, in response to the signal fromthe band suppression controller.

In various alternative embodiments, system and/or device elements,method steps, or example implementations described throughout thisdisclosure (such as any of the master units, remote antenna units,controllers, circuitry, band suppression module, control units orsub-parts thereof, for example) may be implemented at least in partusing one or more computer systems, field programmable gate arrays(FPGAs), or similar devices comprising a processor coupled to a memoryand executing code to realize those elements, processes, or examples,said code stored on a non-transient data storage device. Therefore otherembodiments of the present disclosure may include elements comprisingprogram instructions resident on computer readable media which whenimplemented by such computer systems, enable them to implement theembodiments described herein. As used herein, the term “computerreadable media” refers to tangible memory storage devices havingnon-transient physical forms. Such non-transient physical forms mayinclude computer memory devices, such as but not limited to punch cards,magnetic disk or tape, any optical data storage system, flash read onlymemory (ROM), non-volatile ROM, programmable ROM (PROM),erasable-programmable ROM (E-PROM), random access memory (RAM), or anyother form of permanent, semi-permanent, or temporary memory storagesystem or device having a physical, tangible form. Program instructionsinclude, but are not limited to computer-executable instructionsexecuted by computer system processors and hardware descriptionlanguages such as Very High Speed Integrated Circuit (VHSIC) HardwareDescription Language (VHDL).

Although specific embodiments have been illustrated and describedherein, it will be appreciated by those of ordinary skill in the artthat any arrangement, which is calculated to achieve the same purpose,may be substituted for the specific embodiment shown. This applicationis intended to cover any adaptations or variations of the presentedembodiments. Therefore, it is manifestly intended that embodiments belimited only by the claims and the equivalents thereof,

The invention claimed is:
 1. A distributed antenna system, the systemcomprising: at least one master unit configured to receive a basestation downlink radio frequency signal and to transmit a base stationuplink radio frequency signal; at least one remote antenna unit that iscommunicatively coupled to the at least one master unit, the remoteantenna unit comprising a power amplifier and configured to radiate aremote downlink radio frequency signal from at least one antennaassociated with the remote antenna unit, the remote antenna unit furtherconfigured to receive a remote uplink radio frequency signal from atleast one antenna associated with the remote antenna unit, wherein theremote downlink radio frequency signal comprises a first downlinkfrequency band and a second downlink frequency band and wherein theremote uplink radio frequency signal comprises a first uplink frequencyband and a second uplink frequency band; a band suppression modulecomprising: a band suppression controller; an uplink band suppressionelectronics circuit controlled by the band suppression controller,wherein the uplink band suppression electronics circuit is controlled bythe band suppression controller to pass uplink signals in both the firstuplink frequency band and the second uplink frequency band while in afirst state, wherein in a second state the uplink band suppressionelectronics circuit is controlled by the band suppression controllerapply an attenuation to suppress the first uplink frequency band inresponse to a signal from the band suppression controller while passingthe second uplink frequency band; and a downlink band suppressionelectronics circuit controlled by the band suppression controller,wherein the downlink radio frequency band suppression electronicscircuit is controlled by the band suppression controller to passdownlink signals in both a first downlink frequency band and a seconddownlink frequency band while in the first state, wherein in the secondstate the downlink band suppression electronics circuit is configured toapply an attenuation to suppress the first downlink frequency band inresponse to the signal from the band suppression controller whilepassing the second downlink frequency band.
 2. The system of claim 1,wherein the first downlink frequency band and the first uplink frequencyband define a public safety communications band, and where the seconddownlink frequency band and the second uplink frequency band define aprivate safety communications band.
 3. The system of claim 1, whereinthe band suppression controller comprises electronics responsive to amanagement signal received by the distributed antenna system, whereinthe band suppression controller controls one or both of the uplink bandsuppression electronics circuit and the downlink band suppressionelectronics circuit in response to the management signal.
 4. The systemof claim 1, wherein the band suppression module further comprises amemory coupled to the band suppression controller, the memory storing aplurality of configuration setting; wherein the band suppressioncontroller selectively reads a configuration setting from the memory tocontrol the uplink band suppression electronics circuit and the downlinkband suppression electronics circuit.
 5. The system of claim 1, whereinthe uplink band suppression electronics circuit and the downlink bandsuppression electronics circuit each further comprise: an RF networkelement; and at least one switchable load coupled to the RF networkelement; wherein the band suppression controller is configured tocontrol application of the at least one switchable load to suppress oneof the first uplink signal or the first downlink signal.
 6. The systemof claim 5, wherein the RF network element comprises either a circulatoror a hybrid coupler.
 7. The system of claim 1, wherein the uplink bandsuppression electronics circuit and the downlink band suppressionelectronics circuit each further comprise: a band pass filter; amatching attenuator having an insertion loss equivalent to an insertionloss of the band pass filter; and one or more suppression selectionswitches coupled to the band pass filter and the matching attenuator,wherein the band suppression controller is configured to control the oneor more suppression selection switches to toggle between the band passfilter and the matching attenuator.
 8. The system of claim 1, whereinthe uplink band suppression electronics circuit is further configured topass the second uplink frequency band and the downlink band suppressionelectronics circuit is further configured to pass the second downlinkfrequency band.
 9. The system of claim 1, wherein the uplink bandsuppression electronics circuit and the downlink band suppressionelectronics circuit each further comprise: a first band pass filter; asecond band pass filter; a matching attenuator having an insertion lossequivalent to an insertion loss of either the first band pass filter orthe second band pass filter; and one or more suppression selectionswitches coupled to the band pass filter and the matching attenuator,wherein the band suppression controller is configured to control the oneor more suppression selection switches to switch between selection ofthe first band pass filter, the second band pass filter, of the matchingattenuator, in response to the signal from the band suppressioncontroller.
 10. A method for selectable band suppression for adistributed antenna system comprising at least one master unit and atleast one remote antenna unit that is communicatively coupled to the atleast one master unit, the at least one remote antenna unit carrying aremote downlink radio frequency signal comprising a first downlinkfrequency band and a second downlink frequency band, and a remote uplinkradio frequency signal comprising a first uplink frequency band and asecond uplink frequency band, the method comprising: determining whetherthe distributed antenna system is operating under a first statuscondition or a second status condition; when the distributed antennasystem is determined to be operating under the first status condition,controlling at least one radio frequency (RF) band suppressionelectronics circuit to suppress the first downlink frequency band andthe first uplink frequency band while passing the second downlinkfrequency band and the second uplink frequency band; when thedistributed antenna system is determined to be operating under thesecond status condition, controlling at least one radio frequency (RF)band suppression electronics circuit to pass the first downlinkfrequency band, the first uplink frequency band, the second downlinkfrequency band and the second uplink frequency band.
 11. The method ofclaim 10, wherein the first downlink frequency band and the first uplinkfrequency band define a public safety communications band, and where thesecond downlink frequency band and the second uplink frequency banddefine a private safety communications band.
 12. The method of claim 10,wherein the at least one remote antenna unit comprises a bandsuppression module comprising: a band suppression controller; an uplinkband suppression electronics circuit controlled by the band suppressioncontroller, wherein the uplink band suppression electronics circuit isconfigured to apply an attenuation to suppress the first uplinkfrequency band in response to a signal from the band suppressioncontroller; and a downlink band suppression electronics circuitcontrolled by the band suppression controller, wherein the downlink bandsuppression electronics circuit is configured to apply an attenuation tosuppress the first downlink frequency band in response to the signalfrom the band suppression controller.
 13. The method of claim 12,further comprising: generating the signal from the in response to amanagement signal received by the band suppression controller.
 14. Themethod of claim 12, further comprising: in response to determiningwhether the distributed antenna system is operating under a first statuscondition or a second status condition, reading a configuration settingfrom a memory; and controlling the uplink band suppression electronicscircuit and the downlink band suppression electronics circuit based onthe configuration setting.
 15. The method of claim 12, wherein theuplink band suppression electronics circuit and the downlink bandsuppression electronics circuit each further comprise: an RF networkelement; and at least one switchable load coupled to the RF networkelement; wherein the band suppression controller is configured tocontrol application of the at least one switchable load to suppress oneof the first uplink signal or the first downlink signal.
 16. The methodof claim 15, wherein the RF network element comprises either acirculator or a hybrid coupler.
 17. The method of claim 12, wherein theuplink band suppression electronics circuit and the downlink bandsuppression electronics circuit each further comprise: a band passfilter; a matching attenuator having an insertion loss equivalent to aninsertion loss of the band pass filter; and one or more suppressionselection switches coupled to the band pass filter and the matchingattenuator, wherein the band suppression controller is configured tocontrol the one or more suppression selection switches to toggle betweenthe band pass filter and the matching attenuator.
 18. The method ofclaim 10, further comprising determining whether the distributed antennasystem is operating under the first status condition, the second statuscondition, or a third condition; when the distributed antenna system isdetermined to be operating under the third status condition, controllingat least one radio frequency (RF) band suppression electronics circuitto suppress the second downlink frequency band and the second uplinkfrequency band while passing the first downlink frequency band and thefirst uplink frequency band.
 19. The method of claim 18, wherein the atleast one remote antenna unit comprises a band suppression modulecomprising: a band suppression controller; an uplink band suppressionelectronics circuit controlled by the band suppression controller,wherein the uplink band suppression electronics circuit is configured toapply an attenuation to selectively suppress either the first uplinkfrequency band or the second uplink frequency band in response to asignal from the band suppression controller; and a downlink bandsuppression electronics circuit controlled by the band suppressioncontroller, wherein the downlink band suppression electronics circuit isconfigured to apply an attenuation to selectively suppress either thefirst downlink frequency band or the second downlink frequency band inresponse to the signal from the band suppression controller.
 20. Themethod of claim 12, wherein the uplink band suppression electronicscircuit and the downlink band suppression electronics circuit eachfurther comprise: a first band pass filter; a second band pass filter; amatching attenuator having an insertion loss equivalent to an insertionloss of either the first band pass filter or the second band passfilter; and one or more suppression selection switches coupled to thefirst band pass filter, the second band pass filter, and the matchingattenuator, wherein the band suppression controller is configured tocontrol the one or more suppression selection switches to switch betweenselection of the first band pass filter, the second band pass filter, orthe matching attenuator, in response to the signal from the bandsuppression controller.
 21. A band suppression module for a distributedantenna system, the module comprising: a band suppression controller; anuplink radio frequency band suppression electronics circuit controlledby the band suppression controller, wherein the uplink radio frequencyband suppression electronics circuit is controlled by the bandsuppression controller to pass uplink signals in both a first uplinkfrequency band and a second uplink frequency band while in a firststate, wherein in a second state the uplink band suppression electronicscircuit is controlled by the band suppression controller to apply anattenuation to suppress the first uplink frequency band in response to asignal from the band suppression controller while passing the seconduplink frequency band; and a downlink radio frequency band suppressionelectronics circuit controlled by the band suppression controller,wherein the downlink radio frequency band suppression electronicscircuit is controlled by the band suppression controller to passdownlink signals in both a first downlink frequency band and a seconddownlink frequency band while in the first state, wherein in the secondstate the downlink band suppression electronics circuit is controlled bythe band suppression controller to apply an attenuation to suppress thefirst downlink frequency band in response to the signal from the bandsuppression controller while passing the second downlink frequency band.22. The module of claim 21, wherein the band suppression controllercomprises electronics responsive to a management signal received by thedistributed antenna system, wherein the band suppression controllercontrols one or both of the uplink band suppression electronics circuitand the downlink band suppression electronics circuit in response to themanagement signal.
 23. The module of claim 21, wherein the bandsuppression module further comprises a memory coupled to the bandsuppression controller, the memory storing a plurality of configurationsetting; wherein the band suppression controller selectively reads aconfiguration setting from the memory to control the uplink bandsuppression electronics circuit and the downlink band suppressionelectronics circuit.
 24. The module of claim 21, wherein the uplink bandsuppression electronics circuit and the downlink band suppressionelectronics circuit each further comprise: an RF network element; and atleast one switchable load coupled to the RF network element; wherein theband suppression controller is configured to control application of theat least one switchable load to suppress one of the first uplink signalor the first downlink signal.
 25. The module of claim 24, wherein the RFnetwork element comprises either a circulator or a hybrid coupler. 26.The module of claim 21, wherein the uplink band suppression electronicscircuit and the downlink band suppression electronics circuit eachfurther comprise: a band pass filter; a matching attenuator having aninsertion loss equivalent to an insertion loss of the band pass filter;and one or more suppression selection switches coupled to the band passfilter and the matching attenuator, wherein the band suppressioncontroller is configured to control the one or more suppressionselection switches to toggle between the band pass filter and thematching attenuator.
 27. The module of claim 21, wherein the uplink bandsuppression electronics circuit and the downlink band suppressionelectronics circuit each further comprise: a first band pass filter; asecond band pass filter; a matching attenuator having an insertion lossequivalent to an insertion loss of either the first band pass filter orthe second band pass filter; and one or more suppression selectionswitches coupled to the first band pass filter, the second band passfilter, and the matching attenuator, wherein the band suppressioncontroller is configured to control the one or more suppressionselection switches to switch between selection of the first band passfilter, the second band pass filter, or the matching attenuator, inresponse to the signal from the band suppression controller.